The present invention relates generally to wood posts, and specifically, to a protective sleeve for wood posts used in the construction industry that both increases the life of the post and prevents uplift of the post after it is back-filled.
Post frame construction has become increasingly popular. Unlike conventional framing, in which the frame is supported by a sole plate resting on for example, a concrete or block foundation, in post frame construction the framing is supported by vertical posts imbedded within the ground.
The flexibility of post frame construction makes it particularly attractive for construction projects requiring, for example, big door openings for combines, airplanes, hay trucks, indoor horse complexes, or sports facilities. Often utilized in horse barns, retail, and commercial/industrial facilities, post frame construction is increasingly being used in, for example, country club, church, and residential construction.
Because these wooden posts are embedded into the earth, they are prone to decay at or below the ground line during the life of the post. The rapidity of the decay is generally dependent upon many factors, among them climate and soil conditions. The major cause of deterioration of the post at or below the ground line is attack by fungi, insects or both. Fungi, which are microscopic plants, must have organic material in which to live, and the post offers a food supply. The growth of the fungi is dependent upon the surrounding conditions; growth includes such requirements as air, mild temperatures, and moisture. All of these conditions are generally present in the soil at or just below the ground line of the post.
Numerous methods have been described to provide protection against conditions that promote post deterioration. One such attempt has been to place the embedded post end within a sleeve of high-density polyethylene manufactured from a molding process. The sleeve contains v-shaped in cross section, vertical projecting vents to provide for the escape of exhaust air which may become trapped between the bottom of the post and the bottom of the sleeve.
Another method of attempting to protect wooden posts includes excavating a substantial amount of dirt around the embedded post end to effectuate treating the wood with a preservative, then placing a protective bandage, usually tar paper, around the post, and finally, back-filling the excavated portion around the post.
Still another method of attempting to protect wooden posts is directed to excavating around a post to expose a portion of the post from 1-3 feet, cleaning the post, and then filling the excavation with a foamable resin which 1) foams to completely seal the exposed pole portion from the excavation, 2) fills the excavation, and 3) when the resin hardens, resets the pole in the ground.
Still other attempts to protect wooden posts include a synthetic plastic sleeve formed of synthetic plastic sheeting comprising a liquid impervious, non-biodegradable flexible synthetic plastic film. The film contains a dry film biocide for inhibiting the growth of micro organisms. The sleeve is dimensioned to fit slidably over a timber pole and by heating, to shrink tightly onto the pole.
The prior art attempts to protect wooden posts have all failed to deal with the problem of the wooden post dislodging from the sleeve, or the dislodgment of the post and sleeve as a unit when the structure has been submitted to uplifting or downpressing displacing forces such as that imposed by for example, high winds. During high winds, the design of the structure, particularly if the structure contains overhangs, or if the building is an open-sided pavilion, can act as an airfoil, thereby transmitting substantial uplifting forces to the posts. When these uplifting forces become great enough, the posts can be uplifted completely out of the ground, thereby causing a loss of structural integrity.
To combat these uplifting or downpressing displacing forces, design specifications often call for a hole to be drilled through a portion of the ground insert portion of a post and placement of a twelve inch section of reinforcement bar through the drilled hole prior to cement fill or back-fill. Although the reinforcement bar helps to resist displacing forces, the hole drilled both weakens the post and acts as an entry point for moisture and pests along the reinforcement bar, thus facilitating deterioration of the post.
What is needed is an improved wooden post protector that allows for easy post insertion, protects wooden posts against conditions that promote post deterioration, and at the same time provides increased resistance to post uplifting or downpressing displacing forces.
The present invention is directed to an improved wood post protective sleeve that provides protection against conditions that promote post deterioration, allows for rapid dissipation of trapped exhaust air within the sleeve upon insertion of the post into the sleeve, and provides increased resistance to uplifting or downpressing displacing forces placed upon the post.
In one form, the improved post protective sleeve comprises a body and a plurality of extending displacement resistant projections. The body comprises an internal surface and an external surface with an open end opposite to a bottom wall. The open end slidably receives a ground insert portion of a post.
The bottom wall supports the ground insert portion of the post. At least one displacement resistant projection extends from the external surface, and at least one retainer retains the ground insert portion of the post to the body, preventing the ground insert portion of the post from uplifting out of and separating from the body.
The internal surface has at least one rounded venting channel to provide a rapid escape path for exhaust air trapped within the protective sleeve as the ground insert portion of the post travels downward within the body.
In a different form, the venting channel is omitted.
In still another form of the present invention, there is at least one bottom channel within the bottom wall. This bottom channel communicates with at least one venting channel so as to further assist in allowing trapped air to rapidly escape as the ground insert portion of a post travels downward within the body.
An advantage of the present invention is that the addition of displacement resistant projections, heretofore unknown in the art, helps to resist displacing forces brought on for example, by wind blowing through overhanging architectural designs of buildings being supported by the posts. Unlike reinforcement bar passed through a hole drilled through a ground insert portion of a post, the present invention neither weakens the post, nor allows moisture or pests to enter into the post.
Another advantage of the present invention is that the retainer secures the sleeve to help tie the post into the protective sleeve body and thereby give additional resistance to displacing forces.
Still another advantage of the present invention is that the grooves in the bottom wall communicating with the grooves on the internal surface aid in rapidly directing trapped exhaust air from within the sleeve. As the ground insert portion of the post is inserted into the sleeve, a piston effect is created. Without a means to dissipate trapped exhaust air, the back pressure created by the trapped exhaust air would make insertion of the ground insert portion of the post laborious.
While the prior art has disclosed v-shaped grooves running the length of the sleeve the v-shape has a propensity for debris to become wedged in the xe2x80x9cvxe2x80x9d easily clogging the groove, limiting the rapid escape of trapped exhaust air. An advantage of rounded escape vents is their decreased likelihood to become blocked and clogged.
Still another advantage of the present invention is the addition of grooves in the bottom wall communicating with the grooves on the internal surface, producing greater efficiency in dissipating the trapped escape air.
Other features and advantages of the present invention will become apparent from the following more detailed description of the preferred embodiment, taken in conjunction with the accompanying figures which illustrate, by way of example, the principles of the invention.